This invention relates to the replacement of a well conductor in an offshore platform having several producing oil and gas wells. An oil well is equipped with an inner production tubing position within one or more concentric strings of pipe or well casing which in turn are surrounded by a large-diameter pipe string, known as a "well conductor" which extends from the deck of the platform to several hundred feet into the ocean floor. The well conductor generally supports the weight of the wellhead and at least a portion of the weight of the strings of tubing and casing hung in the well. The well conductor also protects the inner pipe strings from wave action and corrosion.
In the event that a well conductor became corroded, it has been a practice to patch it up by welding more metal over the corroded areas. This calls for underwater welding which is difficult to carry out and inspect, and is not practical on deep platforms which are in 1,000 feet or more of water. For severely corroded or damaged well conductors, it has been the practice to abandon the well and drill another if there is an extra slot or wellbay on the platform.